More than 100 extra staff have been called into Telecom for a second day to deal with call volumes after 60,000 customers had their passwords cancelled over the weekend.

Telecom cancelled the passwords of more than 15 per cent of its 450,000 customers on Saturday night without warning.

Users unable to log on had to change their passwords by answering a number of security questions.

Once they were into their email account, a message from Telecom told them: "We have cancelled your current password and you will need to, or have had to, change your password immediately to use your email account."

Thousands of customers are still reportedly without access to their accounts.